In order to be able to implement an optical coupling between planar LWL components, that is to say optical chips, and assemblies to be connected thereto, it is necessary for the optical chips to be strengthened structurally so that they withstand mechanical loads associated with the connection of optical conductors and other LWL assemblies. For this purpose, the chips are usually constructed in a thickened fashion by providing the entire underside of the respective chip with an additional glass plate which is pressed onto the chip after adhesive material has been interposed. The glass plate stiffens the chip structurally to a sufficient extent such that the latter withstands the mechanical loads to be expected.
Simply pressing the glass sheet onto the chip has, however, the disadvantage that the chip, which has a slightly curved shape because of its customary production process, experiences concave bending and bending back. The latter leads to strains in the chip, and thus to influences exerted on the optical conductors, made from glass, accommodated in the chip, since additional instances of refraction are caused in the optical conductors because of the strains. Furthermore, particularly in the case of optical chips with thermooptical structures, which are necessary, for example, for attenuating or for switching, the glass plate applied over the entire surface of the underside is disadvantageous in thereby worsening the good thermal conduction which is required in the reverse direction owing to the silicon or glass substrate of the chip.